# The Essentials of Plane and Spherical Trigonometry

Leach, Shewell, and Sanborn, 1887 - Trigonometry - 151 pages

### Contents

 PLANE TRIGONOMETRY 1 APPLICATION OF ALGEBRAIC SIGNS 12 MISCELLANEOUS THEOREMS 36 GENERAL FORMULE 43 LOGARITHMS 54 SOLUTION OF RIGHT TRIANGLES 67 GENERAL PROPERTIES OF TRIANGLES 75 12 85
 SPHERICAL TRIGONOMETRY 95 36 113 SPHERICAL OBLIQUE TRIANGLES 114 37 128 FORMULE 137 38 139 ANSWERS TO THE EXAMPLES 144 Copyright

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### Popular passages

Page 1 - To express fractional parts of the unit, the degree is divided into sixty equal parts called minutes, and the minute into sixty equal parts, called seconds. Degrees, minutes, and seconds are represented by the symbols, °. ', ", respectively. Thus, 43° 22' 37" represents an angle of 43 degrees, 22 minutes, and 37 seconds.
Page 107 - If the function is a sine, since the sine of an angle is equal to the sine of its supplement...
Page 104 - I. The sine of the middle part is equal to the product of the tangents of the adjacent parts.
Page 1 - ... is the angle subtended at the centre of a circle by an arc whose length is equal to the radius of the circle.
Page 77 - In any triangle the square of any side is equal to the sum of the squares of the other two sides minus twice the product of these two sides and the cosine of their included angle.
Page 94 - ACB are measured, and found to be 126° 35' and 31° 48', respectively. Required the distance AB. 1. A flagpole 40 feet in height stands on the top of a tower. From a position near the base of the tower, the angles of elevation of the top and bottom of the pole are 38° 53
Page 76 - In every plane triangle, the sum of two sides is to their difference as the tangent of half the sum of the angles opposite those sides is to the tangent of half their difference.
Page 96 - If two sides of a spherical triangle are unequal, the angles opposite them are unequal, and the greater angle lies opposite the greater side ; and conversely.
Page 57 - ... the logarithm of a fraction is equal to the logarithm of the numerator minus the logarithm of the denominator.
Page 116 - A cos 6 = cos a cos c + sin a sin c cos B cos c = cos a cos 6 + sin a sin 6 cos C Law of Cosines for Angles cos A = — cos B...